Dew Point Calculator
Find dew point (°C) from temperature and RH
How to Use This Calculator
1
Enter Temperature (°C)
Type the air temperature in degrees Celsius.
2
Enter Relative Humidity (%)
Provide RH between 1% and 100%.
3
Click Calculate
You will get dew point temperature in °C.
Formula
γ(T,RH) = ln(RH/100) + (a·T)/(b+T)
Td = (b·γ) / (a − γ)
Constants: a = 17.27, b = 237.7 °C
Example: T = 25°C, RH = 60% → Td ≈ 16.7°C
About Dew Point
Dew point is the temperature at which air becomes saturated and water vapor begins to condense. Higher dew point means more moisture in the air.
Why it matters
- Comfort: High dew points feel muggy and oppressive
- Forecasting: Aids in fog, cloud, and storm prediction
- HVAC: Guides dehumidification and ventilation settings
Frequently Asked Questions
Is dew point better than relative humidity for comfort?
Yes. Dew point directly reflects the absolute moisture content; it correlates more closely with human comfort than RH.
What dew point feels uncomfortable?
Dew point above ~20°C (68°F) often feels humid; above 24°C (75°F) is very oppressive.